If you watch the news regularly, you know that every now and then objects — like meteors and satellites — fall from the sky toward Earth. Some people may worry and believe that the sky itself is falling. But is there anything to get excited about?

Believe it or not, space is filled with an almost-unlimited supply of things that could one day fall to Earth. Some of these things are extremely tiny and some are very big. Some are natural and some are man-made.

Scientists believe there are over 20,000 pieces of spacejunk that are at least four inches long. These pieces orbit Earth at speeds of up to five miles per second. Space is also filled with rocks and stones that are called meteoroids.

Occasionally, these things will fall from orbit and enter Earth's atmosphere. Fortunately, Earth's atmosphere protects the Earth from most of these objects.

As they fall, objects meet wind resistance from the air in the atmosphere. This resistance causes friction, which creates heat…A LOT of heat. In fact, most objects burn up completely before they ever reach Earth's surface.

For example, many meteoroids fall toward Earth every day. Most burn up in the atmosphere. If a piece of meteoroid is big enough to survive entry into Earth's atmosphere, its hot, glowing surface may create a moving point of light in the sky as it falls. When we see these, we call them meteors, “falling stars" or “shooting stars."

If a meteor survives its trip all the way through the Earth's atmosphere and actually hits the ground, it's then called a meteorite. Many meteorites reach Earth every year, but the probability of being hit by one is almost zero. Only four people in recent history have been struck by a meteorite, and none were seriously injured.

The odds of being hit by spacejunk are about the same. Experts believe there is only one confirmed case of someone ever being hit by a piece of spacejunk.

In 1997, Lottie Williams of Tulsa, Oklahoma, was hit on the shoulder while walking in the park. Scientists believe she was hit with a part of what used to be the Delta II rocket. The piece of spacejunk weighed about as much as an empty soda can and felt like someone tapping her on the shoulder.

So the next time you hear about a meteoroid or old satellitefalling toward Earth, don't worry. Just remember that the sky is a big place, the surface of Earth is huge and human beings are tiny in comparison. Also, most of Earth's surface is taken up by the world's oceans.

When an old satellite fell to Earth in late-September 2011, the odds of getting hit by debris from the fallingsatellite were about 1 in 100 trillion. By way of comparison, your odds of getting struck by lightning are about 1 in 60,000.

But what about catastrophicmeteorite collisions? For example, scientists believe a meteorite a few miles wide hit Earth about 65 million years ago. It created the Chicxulub crater in the Gulf of Mexico and caused the extinction of the dinosaurs.

Such catastrophic events are extremely rare. Experts believe they only happen every 100 million years or so. So you can rest easy, because we also have a worldwide community of scientists who now keep a close eye on the skies for things that might fall to Earth.

Did you get it?

Wonder What's Next?

Try It Out

Are you up for exploring meteoroids, meteors, and meteorites in greater depth? Find an adventurous friend or family member to help you check out one or more of the following activities:

Ever WONDER what might happen if a meteorite were to hit Earth? Check out the Impact Earth! website to run the numbers on all sorts of different disaster scenarios. For example, you can choose a specific size for your theoretical meteorite, or you can choose a size — from a school bus to the continent of Asia — from the drop-down menu. You can also choose other variables, including impact angle and velocity. Are some of these scenarios scary? What do you think life would be like if a meteorite the size of a school bus hit the continent you live on?

Guess what? Meteorites have hit Earth many times in the past. You can check out the details of Famous Craters from the past. Learning more about these past events can help you predict what future events might look like. Have you ever seen a real crater up close? Do a search online to see if there are any craters near where you live that you could visit.

If you're really worried that the sky might be falling, though, it might be good to revisit the story of Chicken Little (sometimes called Henny Penny or Chicken Licken). You can read The Remarkable Story of Chicken Little online. And remember: when you encounter a “Chicken Little" who tells you the sky is falling, you can always fall back on what you know about probabilities! If you're up for a challenge, you can also make up your own story inspired by Chicken Little that uses real-life events and the facts you learned in today's Wonder of the Day. Have fun and be creative!

Grayson Harmon

Wonderopolis

Unger science class JSH

Nov 22, 2013

WOW I never knew that satellites could fall to Earth! That was really cool. I learn a ton from Wonderopolis. I will have to go to the website more and see what I can find out. Thanks Wonderopolis!!!!!!!!!!!!!!

bcplays

Wonderopolis

Aniziah McCaskill

Aug 8, 2013

The reading on, is the sky falling is really cool I didn't know that little things can fall from the sky and aim at people and the picture was very beautiful. I hope one day I can go to outerspace and discover something new maybe I will go space with friends we will take pictures of what we saw. I will enjoy it if I don't blow up.

addy

adrian

micaiah

Wonderopolis

Aug 8, 2013

WOOHOO we love your thoughts and connections in your comments today, Jessica, Elizabeth, and Micaiah! You've done a great job sharing what you've learned today and we hope to Wonder about another cool topic with you soon! :)

Elizabeth

Jessica

Aug 8, 2013

This article taught me a lot about space junk and reminded me about Chicken Little. I also wonder why the stars move and how hot they are. 8-) I didn't know that there was so much space junk. I loved the video too. This article is fabtabulous xD !!!!!

DeMetrius

Aug 8, 2013

connection: my connection is that the sky is falling is off of Chicken Little. But the video is boring because they only showed rocks in space they should have showed a meteoroid on fire going to Earth.

Wonderopolis

Aug 8, 2013

Space junk is made of lots of things, sometimes it's pieces of old weather balloons, satellites, and even meteorites! We love your connections to our space Wonder, Carlos, Kayla, and DeMetrius! Thanks for WONDERing about space junk with us today! :)

romen

Wonderopolis

Aug 8, 2013

Great connections and questions, Donavin, Micaiah, and Romen! We have been thinking a lot about Chicken Little and the phrase "the sky is falling" today! We're glad you have been, too! We've been WONDERing about gravity, which is a reason that objects fall from the sky. Have you checked out Wonder #372-- When is it Good to Be Grounded? https://www.wonderopolis.org/wonder/when-is-being-grounded-good/ :)

Donavin

Mackenzie(Mr.komlers' class)

Wonderopolis

Aug 8, 2013

Thanks for telling us about what you learned today, Wonder Friends Donavin, Kamarien, and Mackenzie! It sounds like you've learned a lot from today's Wonder-- we'll keep our eyes peeled for space junk from now on! We love reading your comments and can't wait to Wonder with you again! :)

Donavin

adrian

adrian

Wonderopolis

Aug 8, 2013

Thanks for WONDERing with us about "space junk" today - we're glad that the sky is NOT falling! However, sometimes things do fall from the sky, with the help of gravity. We look forward to WONDERing with you again soon! :)

yossi

Wonderopolis

Aug 5, 2013

Great question, Yossi! We are glad you enjoyed our Wonder and you've been thinking about how the sky is recorded so quickly. The type of technique the video features is called "time lapse" - this technique speeds up the video recording so it looks like the sky is moving super fast! Pretty neat, isn't it? :)

joe

Wonderopolis

Oct 23, 2012

Hi there, Joe! We sure are glad you're shooting for the stars today-- you've been doing a great job of WONDERing! :)
The great thing about Wonderopolis and the internet is that you can check out cool things, like shooting stars, even if you can't see them in person! Perhaps you'll see a shooting star in person, but in the meantime, you can use technology to see one on the computer! :)

nick

Wonderopolis

Dec 16, 2011

Hi, Nick! Thank you for leaving us this comment and for letting us know you might be a little confused about something found in this Wonder. Can you let us know what doesn't make sense to you so we can help explain it better? :-)

Wonder Friend

Wonderopolis

Dec 6, 2011

That's right, Wonder Friend! Chicken Little was a wee bit over-excited about the sky falling. We're sure glad we learned that the sky isn't really falling and also that we got to learn about cool stuff like space junk and meteoroids, aren't you? :-)

farmington school

Wonderopolis

Dec 3, 2011

We're so happy to count you all as Wonder Friends, farmington school, and think it's AWESOME that you love Wonderopolis and learning new things! Thank you for letting us know you live in Wisconsin. Is it very cold there this time of year? :-)

mak

micaiah

Wonderopolis

Aug 8, 2013

Way to go, Wonder Friends Adrian, Addy, Aniziah, and Micaiah! You learned a lot with us today AND you have even more questions about this Wonder! How cool! We hope you'll do some more WONDERing of your own with the help of the Internet and your school's library! Keep using your imaginations! You can do it! :)

Anthony

Dec 1, 2011

Why is it that a meteor, meteorite and meteoroid are different things, but are technically the same thing coming from space? How big does the meteoroid have to be to be able to get through the atmosphere?

Wonderopolis

Dec 1, 2011

You ask some really great questions, Anthony! We found this web page on the NASA website for you to visit so you can WONDER even more about meteoroids: http://starchild.gsfc.nasa.gov/docs/StarChild/solar_system_level2/meteoroids.html. Thanks for visiting Wonderopolis today and for being a GREAT Wonder Friend! :-)

Meg

Wonderopolis

Dec 1, 2011

We're super glad you checked us out, Meg...THANKS! Wonderopolis is a place where students, teachers and parents can all learn together EVERY DAY! We have been around for over a year now, and there are lots of cool people who work here in Wonderopolis to make sure that each new day's Wonder is, well, WONDERful! We have over 400 Wonders of the Day to explore, so have FUN checking them out, too! Thank you again for visiting!

Meg

Wonderopolis

Nov 29, 2011

Hello, Meg! We're not sure if dogs and cows are related, but we appreciate great WONDERing from our Wonder Friends (like you!)! Thanks for visiting this Wonder of the Day® and for leaving us a comment! :-)

Wonderopolis

The Class from Room 234 Dublin...

Nov 29, 2011

Today is our first day on Wonderopolis as a class and it brought out tons of questions and thoughts. We learned that most meteoroids never make it to Earth. We also liked calculating how fast meteoroids travel per hour. 18,000 mph... WOW! We wish that we could see stars like in the video. Where we live, they have light pollution rules, so we get to see more stars then in the nearer cities. We loved the link to impact earth. The rock looked like a potato. We are still wondering if stars move?

Wonderopolis

Nov 29, 2011

You sure DID have a lot of questions and thoughts after exploring today's Wonder, The Class from Room 234 Dublin, Ohio. We appreciate your comment very much! Thank you for sharing all the neat things you learned today! We will have to do some more WONDERing ourselves to find out if stars move. In the meantime, you might like visiting past Wonder of the Day® #182 - How Many Stars Are In the Universe? Here's a link that will take you right to it: https://www.wonderopolis.org/wonder/how-many-stars-are-in-the-sky/. Happy stargazing! :-)

rachel

Wonderopolis

Nov 29, 2011

Hi, Rachel! You can rest assured that we're real people here in Wonderopolis! We want to make sure we give each comment the time and appreciation it deserves, so we might not be able to reply right away to any specific comment. But, we will ALWAYS reply to every real comment! Wonder Friends from all over the world comment each day on whichever one (or more) of the 400+ Wonders of the Day® they are exploring. That's a LOT of comments from a LOT of Wonder Friends! :-)

Kerrick Elementary School

Nov 29, 2011

We really liked the video today! The music and the scenery were fascinating! :)
We talked about how things have fallen from the trees and how it sometimes hurt. Many of us shared that we would think something falling from the sky would hurt a lot. However, we thought it was interesting that Lottie Williams got hit by space junk and said it was like being tapped on the shoulder. We took turns tapping our partners lightly and agreed that we would have thought space junk would have hurt much more than that. :)
We also read the Remarkable Story of Chicken Little. Almost all of us have seen the movie Chicken Little but many of us had never heard the original story. My was it different! Some of the boys (and a few girls) liked the original story of Chicken Little better. Our teacher said she liked the movie better because the story was violent and some of us agreed. :) Thanks again for another great wonder that gets us thinking, discussing, and connecting to the world around us. See you Thursday! :)

Wonderopolis

Nov 29, 2011

Thank you SO MUCH for sharing another great comment with us, Kerrick Elementary School! We have watched the video for today's Wonder several times...it's mesmerizing! We think it was super cool that you tried to feel how Lottie Williams felt when she got "tapped on the shoulder" by space junk! You guys sure know how to WONDER! :-)

We REALLY enjoyed this wonder! We like to learn about space, because so much is unknown. We do not really worry about things or objects from space falling on us. This did, however, lead us to wondering if the Earth be destroyed by an asteroid? What about black holes? Is there one in our galaxy and could it pull in the Earth? Is there a way to retrieve the space trash we have left out there? Can we colonize the MOON? :-) Thanks!
--Team Turner

Wonderopolis

Nov 29, 2011

You guys have REALLY impressed us all here in Wonderopolis with your extra WONDERing about space today, Team Turner! Those are all EXCELLENT questions, and would make great future Wonders of the Day®! Thank you so much for sharing all the things you WONDERed about after you visited today's Wonder! :-)

Raina

Nov 29, 2011

The pic is awesome and pretty, but the video wouldn't load... :( But ,I did read the whole thing, and it was fascinating! Now I can tell my sis not to freak out when she hears that a satellite is falling to Earth! :) By the way, I am 11, and home-schooled, and my mom showed me this website called oneword.com. Its really fun!

Wonderopolis

Nov 29, 2011

Thank you so much for leaving us this awesome comment today, Raina! Tell your mom that we really appreciate her sharing Wonderopolis with you and your sister...we LOVE meeting new Wonder Friends and learning together each day! We think it's cool that you are 11 and are home-schooled. Thanks for sharing about oneword.com, too! You're right! It IS fun! :-)